I have noticed a dramatic increase in front tire noise on my '01 4x2 Screw over the last couple of months. The dealer here claims that the "front tires are cupped because they were not rotated". One small problem, cupped tires are not caused by not being rotated! The dealer refused to help (His words were "there is nothing I can do"). The only thing that he did do was look at the tires (just a quick visual). I only have 13,000 miles on the truck and don't think I should have to be replacing the tires with such low mileage (tires are General Grabbers AW). Any suggestions???

 

YEAH, TAKE THE TRUCK TO A GOOD FRONT-END SHOP AND HAVE THEM CHECK THE IDLER AND PITMAN ARMS. BET THEY HAVE MOVEMENT IN THEM. AND THAT'S THE PROB. FORD WON'T ADMIT IT, BUT THAT'S WHERE THE PROB LIES.

 

I have an 01 4x2 with the General Grabbers AW. I now have 24K on mine. I am starting to get some cupping as well but only in the last couple of months. I noticed the other day that there was one tread on the outside of the front left tire that was say 3/16ths proud of the one next to it. The others were pretty uniform. Any ideas as to a cause? I had the tires rotated at 12K or so and plan to do it again soon.

I think it might be a tire problem. I have had three sets of General tires on 3 different vehicles and they have all had cupping problems. One of the vehicles has had 2 other brands with no cupping problems whatsoever.

I think I have actually seen a poster a tire shop that showed cupping and said it was due to not rotating the tires.

I know one thing. The drone drives me nuts once it starts and it never seems to get better if you rotate, balance or have an alignment done.

 

i have the stocker GoodYear's on and at about 20,000 they too started showing some cupping. I just keep rotating them!

Tony

 

I purchased my truck with 10,500 miles. Before I purchased, I noticed that the driver-side rear tire was cupped (crappy Goodyears) and I knew that it must have been on the front.

One of my purchase requirments was a front end alignment. The following week when the alignment was performed, I was told I received a 4 wheel alignment - I didn't even know that it was possible to align the rears.


Anyway, I have 19,500 miles now and I do not have any cupping on any of the other 3 tires.

 

Here's a dumb question but, I believe the only stupid question is the question you don't ask...


What's cupping?

 

A four wheel alignment does not always mean that the rear was "adjusted". All it really means is that there were 4 alignment heads mounted on the vehicle. The rear ones tell which way the rear tires are pointed. Surprisingly they may not point exactly the same direction as the front tires. This measument of the direction of the rear tires is used to calculate the "thrust angle". The thrust angle is an angle that is formed from the centerline of the vehicle and the real direction the tires are pointed. Knowing this angle the front alignement angles can be adjusted (as well as the rear if possible or easy) to make the vehicle go straighter and have better tire wear.

 

I too bought my S'Crew from the dealer as with 5000 miles on it, have rotated the tires every 10,000 miles, and have had them balanced each time. I now have about 28K on it and the tires that were originally on the front are cupping badly and the other two are starting to cup. The first two are so noisy, I just had them put on the rear. It's still noisy but not as bad. AND it doesn't resolve the problem, whatever it is. HELP!

 

Don't wait until 5000 miles to rotate your tires. If your truck is aligned perfectly, cupping can still develop...normal everyday turns on streets and parking lots wear the tires causing the tread blocks to feather and cup. Then, when driving on the highway, the cupping is accentuated even more. Once cupping starts, it's virtually impossible to reverse.

The best bet is not to allow cupping to begin in the first place and the way you do it is by maintaining the correct pressure and rotating your tires every 2500 to 3000 miles max. Tire shops will tell you 5000-7500 miles is fine for rotations...for a car maybe, but we are talking about a very heavy truck here!

My Grand Cherokee with perfect alignment/tire pressure etc. would eat tires...had to rotate them every 2500 miles to avoid cupping.

To me, tire rotations are like the oil change schedules...5000 miles if all you do is highway driving...2500-3000 miles if you do anything else.

 

18,00 miles on my 4x2 and haven't rotated tires yet and they still look new, boy you guys with all that crap on them like front end guards and stuff just don't get it. The more crap you put on it the heavier it weighs. DUH!

 

I agree with ZJumper -- and have seen good service on tires that are frequently re-balanced.

A zillion years ago, I balanced many many tires with the Hunter on-the-car/truck spin-balancer (the one that could decapitate you if you forgot to lock the adjustment cams) -- and truly miss not having one at my disposal today.

There's something 'magic' that occurs around 70 MPH (and 35 MPH) -- and when you balance a tire around that speed (the max vibration point was easily found on rear tires when you used the car's engine/speedometer to find the 'spot'), the vehicle seems to float on air.

 

I do not know either, maybe somebody will tell us.

 

Cupping is uneven tire wear. The easiest way to explain it is, think of a tire as round, now picture a Stop Sign. (exxagerated)

Some other possible causes are:

loose wheel bearings
mismounted tire/ wheel assembly
out of balance wheel assembly
worn bearings, shocks, springs or other suspension components

 

O.K., It's been a while since I studied the subject, but I thought "cupping" was actually circular concave depressions in the tread (causing the tread to thin locally). If I remember correctly, the tire companies used to blame this on poor shock absorbers. And if we follow that logic, shocks are actually "spring dampers" (limiting unnecessary motion in the suspension), then the "loose or worn suspension component" explanation would bode well. I also believe that some "cupping" is the result of "soft spots" in the tire, and may not be the fault of Ford.

I would have my front end inspected (by someone I trust) if cupping existed.

I have always seen "feathering" of my tires, no matter what vehicle I was driving. "Feathering" is the tapered wear seen on the tread blocks of front tires (resembling sawteeth) caused by the leading edge of the tire wearing faster than the trailing edge. This is caused primarily by "tight" cornering, and may be exacerbated by the limited slip differential.

All suspension geometrys (except for casters) have some degree of "slip angle" built in. It is nearly impossible to get the center of rotation of the rear tires to align with the center of both front tires. If the slip angle is too great, the tires wear poorly in a straight line, too little and the car "binds" in a corner.

Frequent rotation (if you do a lot of cornering) is probably the only reasonable thing you can do for "feathering".

 

Nice post Noah'sDad but, I get extra credit for my 'Stop Sign' visual.